Actually. I just figured out I don't.
March 2002 I dropped about 30$ on a Civilization 3 game. The guy had a picture of the game and all. I got a version which I found strange. It had a small instruction page that told how to install the game. It looked official just like the CD. Both had game screenshots (the little piece of paper) along with Sid Meier's name and Civlizaiton 3. The CD was the same. It included the Firaxis and Infogrames logo on it. A little art on the CD and "Sid Meier's Civilization 3" printed on it.
I never suspected anything till I downloaded 1.29f and found out the CD wasn't being read correctly. It kind of raised a red flag, but I ignored it. I just downloaded the No-CD and assumed it'd all be alright. Now that you've pointed this out, I took a closer look and found a small text file that a group of hackers 'ripped" this game to their own version. I'm really annoyed for having dropped $30 on what I thought to be a legitimate version. Oh well...Looks like I've gotta go buy a new copy :/
Thanks for all the help.